VII. Answer to Abgar's letter, which the apostle Thomas wrote to this prince by command of the Saviour.
“Blessed is he who believes in me without having seen me! For it is written of me: 'Those who see me will not believe in me, and those who do not see me will believe and live.' As to what you have written asking me to come to you, I must accomplish here all that for which I have been sent; and, when I shall have accomplished it all, I shall ascend to Him who sent me; and when I shall go away I will send one of my disciples, who will cure your diseases, and give life to you and to all those who are with you.” Anan, Abgar's courier, brought him this letter, as well as the portrait of the Saviour, a picture which is still to be found at this day in the city of Edessa.
Source: History of Armenia (New Advent)